Stone polishing machine



March 9, 1937. w. e. CUMMING STONE POLISHING MACHINE Filed Feb. 18, 1936 wilza Patented Mar. 9, 1937 PATENT OFFICE STONE POLISHING MACHINEWilliam G. Cumming,

Barre, Vt., assignor to Granite City Tool Company, Barre, Vt., acorporation of Vermont vApplication February 18, 1936, Serial No. 64,431

1 Claim.

This invention relates to stone polishing ma.- chines of. the typeemploying polishing wheels which rest on the stone and rotate aboutvertical axes, the wheels comprising a disk having eccentric scrollsattached to their lower faces and operating upon the stone through themedium of iron shot or other abrasive material.

Objects of the invention are to polish convex, concave or other warpedsurfaces, to facilitate the manipulation of polishing wheels of the typereferred to, to reduce the vibration and tendency of the wheels tochatter, to increase the quality and rate of polishing, to prolong thelife of such machines and generally to improved the art of stonepolishing.

The present invention comprises a horizontal beam with means foradjustably supporting the beam for endwise movement, one end of the beamcarrying means for supporting a polishing wheel for rotation about avertical axis and the motor for driving the wheel preferably beingmounted on the other end of the beam. The beam is supported intermediateits ends for horizontal swinging and for vertical tipping. The

preferred means for this purpose comprises a support pivoted about ahorizontal axis to a stub shaft extending upwardly into a sleevecontaining bearings for the shaft, at least one bearing being arrangedto support the shaft in the sleeve.

In the preferred embodiment the supporting means is carried by a cranewhich is adjustably mounted on an upright so that it may be raised andlowered and also swung horizontally.

The invention also comprises means for adjusting the aforesaid beamendwise on its support. This means comprises a part fast to the beam, apart fast to the support and interconnecting means for producingrelative movement of the parts toward and from each other. Morespecifically said means preferably comprises cable wheels mounted on thebeam on opposite sides of the support. together with a cable extendingaround the wheels and having its ends attached to the support and meansfor rotating one of the wheels. The wheel to be actuated is preferably asprocket wheel and at least that portion of the cable cooperating withthat wheel comprising a chain meshing with the sprocket wheel.

Other aspects of the invention will appear from the followingdescription and the accompanying drawing of one concrete embodiment. Inthe drawing,

5 Fig. 1 is a. front elevation of the machine;

Fig. 2 is a section on line 2-2 of Fig. 1; and

Fig. 3 is a section on line 3-3 of Fig. 2.

The particular embodiment of the invention chosen for the purpose ofillustration comprises an upright 1 upon which the crane 2 is mountedfor vertical movement and also horizontal swinging. Vertical movement ofthe crane is facilitated by means of two rollers 3 engaging oppositesides of the upright I and the crane is maintained in horizontalposition by means of a brace 4 connected at its lower end to a sleeve 5surrounding the upright I. Two sheaves 6 are mounted on the upper end ofthe upright by means of a bracket 1 and another sheave 8 is mounted onthe upper side of the crane 2. A winding drum 9 is mounted on the craneadjacent the upright and is arranged to be rotated by means of a motorIll connected to the winding drum through the medium of .a worm H andworm-wheel l2. A cable [3 extends around the sheaves 6 and 8 and aroundthe drum 9, one end of the cable being connected to the bracket 1 andthe other end to the drum 9. Thus when the drum 9 is rotated in onedirection the crane is lifted by winding the cable around the drum, andwhen the drum is rotated in the opposite direction the crane is loweredby unwinding the cable.

Depending from the outer end of the crane 2 is a sleeve I4 containingtwo anti-friction bearings l5 and NS for the swivel shaft I1, the upperbearing being arranged to support the shaft. Mounted on the lower end ofthe swivel shaft IT, by means of a horizontal pivot pin I8, is a supportl9 carrying four rollers 20. Mounted upon these rollers is a horizontalbeam comprising two channel members 2| having their flanges directedinwardly over and under the rollers 20, the two channels being tiedtogether by straps 22 underneath the channels. Mounted on the upper sideof the horizontal beam on opposite sides of the support I9 are a sheave23 and a sprocket wheel 24. Extending around these two wheels is a cablehaving its opposite ends connected to the support Hi, the portion 25 ofthe cable cooperating with the sheave 23 comprising steel wire and theportion 26 of the cable cooperating with the sprocket wheel 24comprising a chain meshing with the teeth of the sprocket wheel. Thesprocket wheel 24 is arranged to be rotated by means of a handwheel 21kinematically interconnected with the sprocket wheel through the mediumof a shaft 28 and worm gearing 29.

Mounted on one end of the beam 2| is a gear casing 30 containing bevelgears 3|. Extending downwardly from the gearing 3| through a bearing inthe lower side of the casing 30 is a shaft 32 which is connected to thepolishing Wheel 33 through a flexible coupling 34. Adjacent the casing30 is an abrasive reservoir 35 having an outlet duct 36 for delivering"abrasive through openings in the top of the polishing wheel 33. Mountedon the other .end of the beam M is a motor 31 'whichis interconnectedwith the gearing 3| through the medium of shaft 38 and flexiblecouplings 39 and 40. By providing a flexible coupling at each end of theshaft 38 vibration of the apparatus is greatly reduced.

The beam 2| carries a bail-like handle 4| for manipulating the wheel 33over the slab of stone 42 mounted on block 43 within an enclosure 44.The beam also carries, adjacent the handle 4| and the handwheel 21, twoelectrical control devices 45 and 46 for the motors I0 and 31respectively.

From the foregoing it will be evident that a single operator standingoutside the enclosure 44 adjacent the'handle ll can readily manipulatethe entire apparatus'from this one location, raising and lowering thebeam by means of motor I!) and control 45, starting, and stopping thewheel by means of motor 31 and control 46, adjusting the beam lengthwiseon the support I 9 by means of the handwheel 2'! and swinging the beam2| horizontally by means of thehandle 4|. Thus the polishing wheel 33may readily be placed on the slab ofstone 42 and then easily manipulatedover the upper surface of the slab, the motor 37 tending tocounter-balance the parts carried by the other end of the beam. It willalso be evident that my improved machine is especially adapted to polishwarped surfaces, or fiat surfaces which are not level, as well as flatlevel surfaces, without any change in the machine in changing from onetype of work to another.

It should be understood that the present disclosure is for the purposeof illustration only and that this invention includes all modificationsand equivalents which fall within the scope of the appended claim.

I claim:

A stone polishing machine comprising a normally fixed overhead carrier,a substantially ver tical sleeve having its upper end fixedly secured tothe carrier, a freely rotatable swivel shaft within the sleeve,antifriction bearings for the swivel shaft disposed within the sleeveadjacent the opposite ends of the latter, one at least of said bearingsbeing constructed and arranged to support the weight of the swivel shaftand parts carried by the latter, a support, and a pivotal-connection souniting the support to the lower end of the swivel shaft as to permitthe support to tilt about a horizontal axis, a. beam structure includinga pair of substantially par-allel rigidly connected channel members eachhaving its flanges directed inwardly toward the other channel member,two pairs of rollers mounted on the support, said pairs of rollers beingdisposed between the flanges of the respective channel membersfbearingmeans adjacent to one end of the beam structure for' a normally verticalpolishing wheel shaft, a polishing wheel on the lower end of the lattershaft, means adjacent to the opposite end of the beam structure forsupporting a driving motor, drive connections extending longitudinallyof the beam structure from the motor to the polishing wheel shaft, andmanually actuated means, reacting between the support and beam structurewhereby the latter may be moved longitudinally relative to its support.

G. CUMMING.

